Known drum type fluid pumps generally have a propeller mounted on a drive shaft for moving fluid through the pump. The shaft is rotatably mounted on bearings spaced along the axial length of the shaft and is contained within a support tube. The bearings are generally of a ball or roller type which must assume a precise fit between the shaft and the tube. Accordingly, one disadvantage associated with such pumps is that they are both complicated and expensive to manufacture.
The German patent No. 2,750,801 shows a pump having a shaft supported within a tube and a plastic hose situated between the shaft and the tube which acts as a bearing. One problem associated with this type of pumps that particles within the fluid being pumped may form deposits between the plastic hose and the shaft, as well as between the hose and support tube. Such deposits are generally not removed by the flow of the fluid being pumped, nor can they be removed by simply rinsing the pump, and accordingly can cause premature pump failure.
It is an object of the invention therefore to provide a fluid pump that overcomes the above mentioned problems and disadvantages of known fluid pumps.
It is a further object of the invention to provide a fluid pump having a rotatably mounted drive shaft contained within a support tube wherein fluid particle deposits will not form around the shaft and which can be simply and economically manufactured.
Other objects and advantages of the invention will become apparent in view of the detailed description below and drawings taken in connection therewith.